Honda CB 550F
Testers: Peter Watson, Graham Sanderson
The Atlantic for five years except that in the States it was transformed into the CB550 in 1973 and, subsequently, the CB550F last year. So the latest derivative we've got over here is more than just an upstaged CB500. Having been though its transition period as the CB550 in the States, the bike is just about on the ball and it's been well worth the wait.
Honda now appear to be designing machines specifically for the European market rather than merely insulting European taste with that sit - up - and - beg riding position that the Yanks love so much. It's a trend we noticed with the CB400 first tested in these pages in July '75 and which became consolidated in the CB750F, a greatly improved version of four-piper CB750s.
Seating position on both the 400 and the new 750 was good and it's equally accommodating on the CB550. Footrests sprout just to the rear of the engine and the rider leans slightly forward on to the handlebars raised a couple of inches above the head-stock. The bars are wide enough to afford bags of control through the turns, yet they're sufficiently narrow to maintain the rider's body in aerodynamic' balance for those long motorway bashes.
I can almost hear the potential customer mulling over the comparisons between the 40 lb lighter and, at the time of writing, £166 cheaper CB400, and the heavier and £250 more expensive CB750, as well as pitching it alongside the GT550 Suzuki. Yet the CB550 is much more than just an in-bet weenie in the Honda range; more than merely a compromise between 750 cc beef and 400 cc cheap thrills. We believe the CB550 provides one of the finest balances between performance, economy and handling quality in today's motorcycling arena. That may sound like a tribute normally reserved for the two grand-plus machine, but we thoroughly enjoyed the CB550 and consider it to be one of the better bikes to emerge from Honda's design team in recent years.
At £975, the CB550 is cheap enough to fall within easy HP reach of most bikers and possesses performance that makes you wonder why you ever considered buying the
CB750. We dubbed the CB400 a Poor Boy's Musclebike; the CB550 is that and more. More weight, more muscle, more torque and more pure motorcycling enjoyment.
Thumbing the starter button on the right of the handlebar induces the crank to revolve and the Honda ticks over with the precision of a quartz wristwatch. Yet such is the efficiency of the fashionable four -into - one exhaust system that it creates a false impression that the 550's.engine is mechanically noisy.
Round town the Honda felt more like the 750 than its smaller 400 cc brother, yet it was maneuverable and the tractability of second and third gears provided the right combination of acceleration with minimal use of revs. However, continuous subdued start-stop riding showed up a couple of flat spots below 5,000 rpm and with an overly strong throttle return spring I occasionally grabbed more revs than was really necessary. Still, right down to walking pace the machine felt balanced. Even tall dwarves of 5 foot 6 inches can foot their way through the traffic with a seat height of 31 inches.
But it's out town where the fun really begins. Wind open the throttle to around 5,500 rpm and the Honda begins to come on strong. There's no power surge, just an enthusiastic urgency about the way the revs climb usefully to 8,500 rpm before power tails off. Revving to the 9,300 rpm red line has little effective value in terms of road speed and merely increases petrol consumption. All the time the exhaust remains quiet and the rider, in helmeted isolation, is barely aware of the high-pitched but heavily muffled scream that inoffensively finds an orchestrated passage through the system. There's just a faintly perceptible mechanical rustle from the motor to keep the rider company.
Performance is not excessive but at least it's all usable and it's available in quantities that will please all but the looniest speed freaks. The Honda nips up to well over 90 mph — VASCAR permitting — at any time of asking and keeps up 70 mph at a leisurely 6,000 rpm in top. Yet if you're anxious to find that extra 10 to 15 mph on top speed the throttle has to be screwed
viciously and fuel consumption rises in sympathy. When that's all in aid of knocking a couple of minutes off your ETA the strain seems to be an exercise in pointless-ness. Tramping hard along the M4 unmerci-lessly using revs, the Honda struggled to average 38 mpg. Even with more subdued and realistic riding, petrol consumption only staggered into the low forties. That's the price of performance, but proved quite acceptable in the Honda's case.
The frame is basically identical to that used on the CB500, although the front forks have come in for some internal redesigning and the rear suspension units have been uprated and more heftily sprung. The Honda's performance, sporty appearance and excellent seating position encourage spirited riding, but push the 550 to its limits and you'll discover that the handling isn't quite up to the standard it's led you to expect. Chasing hard into a bend, braking, changing down and peeling into the turn in one swift motion induces a tail-end wiggle which serves as a warning that the CB550 is not, after all, a GP racer. Brake and change down well before you're into the neck of the bend, accelerate right through it and the Honda drives round just dandy. It's just a question of tuning your own riding style and abilities to tit the feel, performance and handling of the 550. Once you've done that you'll discover how easy it is to drag the collector box across the blacktop on right-handers, contrasting with the much better ground clearance on the spartan but functionally attractive left side of the bike. Comments on roadholding have to be subjective in this instance since our test machine was shod with a pair of nonstandard Continentals which broke away on several occasions in the dry. Wet weather performance remained untried due to the total lack of rainfall during the test period.
The brakes have evidently been set up to suit the machine's bulk and potential performance. Grabbing a fistful of the 11 inch front disc from any speed left it fade- and grab-free, and the rear drum brake just helps keep things in a straight line when you begin to stand the 550 on its front wheel.
Exterior dimensions of the 550 motor are identical to those of the CB500 but internally there have been many modifications. The clutch and gearbox have come in for some particularly extensive revision. The engine was hogged out by 2.5 mm per bore raising the capacity to 544 cc. and max torque output moved 500 rpm down the scale to 8.500 rpm.
Numerous styling changes have given the CBS50 a fresh, polished image. Its reshaped petrol tank now holds 3.7 gals and the toolkit is housed on the underside of the seat. Out front there's a large twin-dial setup of speedometer and rev-counter, with an idiot light console neatly tailored to go in between them. The 550 shows its American connection only in the tiller cap, which in bath-plug style is chained to the inside of the tank, and in the flap which hides the whole caboodle.
We tried to find serious fault with the 550 and failed simply because it's a competently designed motorcycle. Okay, so maybe the seat is an ass-deadener after 100 miles, and the rider is always aware of a high frequency buzz too fine to be called vibration, but nevertheless noticeable. But apart from the bleeping turn indicators the CB550 is not plagued with gimmicks. The styling is clean, even subdued, available only in just blue or orange. No flashes, no stripes, no unnecessary fuss.
The CB550 is an enjoGraham Sandersonyable motorcycle to ride because it's so "together": each facet of its design complementing the next. In the same way that the RD400 is the optimal development of the road-going two-stroke, we reckon the CB550 enjoys similar status in the four-cylinder four-stroke market, at least in the sub-900 cc category.
Source Bike Magazine 1975
THE SPORTING MIDDLEWEIGHTS
• The Suzuki GT380 Sebring was the first sub-400cc street bike to break away from the 350cc class rating. It was also the first mid-displacement multi-cylinder roadster from Suzuki. In the wake of the performance bikes of the early Seventies, the Sebring navigated in a very different direction, and moved toward serene performance and exceptional comfort.
In designing the GT380, Suzuki's engineers mixed fresh concepts with proven parts. The bore and stroke of the Sebring are the same as Suzuki's 250cc street twin. By adding one cylinder the displacement was bumped up to 371 cc. Mild port timing, low compression and small carburetors level out the 380's power and separate it from pipey, performance-type two-stroke engines.
The six-speed gearbox is also of the same design as the GT250 twin's. Gear spans are progressively tightened up in the higher cogs and there's nothing unusual about that, but it does allow a rider to find a gear in which the GT380 is absolutely smooth on the highway.
For all intents and purposes the engine has remained unchanged since its release in 1972. The Ram Air System has proved efficient in increasing engine heat dissipation, and more importantly, reducing operating noise. The low compression motor runs trouble-free on regular grade gasolines. Suzuki's intricate oil injection system lubricates the pistons and crankshaft bearings individually and includes a recycling arrangement which removes fuel mixture accumulation from the crankcase areas and feeds it directly into the combustion chambers.
In 1974 a number of major changes were made to the chassis, carburetor intake, exhaust and instrumentation. The chassis was completely redesigned to improve handling and ground clearance. Better fork internals, shock dampers and springs delivered a better ride. New instruments were joined by the digital gear readout and larger warning lights.
Bell-crank operated carburetors replaced the cable-actuated mixers and the mufflers were moved up and in for additional ground clearance. Modifications to the intake system reduced objectionable induction drone and relocated footpegs and controls increased comfort.
Suzuki built the Sebring with a front drum brake only in its first year, moving to a disc in 1973. Rubber engine mounting is unchanged, having proven effective in eliminating vibration. The conventional triple-point ignition system is driven from an independent idler gear to prevent timing fluctuation associated with crankshaft flexing.
Initial saddle and gas tank designs have gone without alterations. Minor design improvement changes have been made to the GT380's through its five model series, but few are visible. Suzuki believes in improving the breed from the inside out, not the outside in. The GT380 has successfully survived four tough years, and Suzuki appears willing to retain the Sebring indefinitely.
• There is little new and nothing unconventional about the '76 Suzuki GT550
Indy. It is a four-year old motorcycle that was designed to ride the waves of progress, survive as a seasoned veteran and never get out of date. Paint scheme alone identifies the 1976 Indy as new.
Suzuki's innovative design of the Ram Air cylinder head shroud system has endured, unchanged, since the beginning. Ahead of its time in 1972, the RAS provides dual benefits. The scoop increases air-flow activity over the fins, and also functions as an excellent sound-deadener to minimize the amount of top-end piston noise.
There have been no performance changes made to the cylinders or pistons since the Indy's inception. The low-compression two-stroke triple was designed for durability and runs as happily on low-or no-lead fuels as it does on premium. Unchanged since the GT550's original design is its exceptionally effective rubber mounting system.
Only one chassis change has been made to the GT550 through the five-model series. In 1974 a number of major up-dates were built into the Indy—mostly to subdue noise and improve handling. The carburetion, intake and exhaust systems were modified to reduce operating noise levels. The exhaust pipes were tucked up closer to the frame, the side stand and center stand were moved in and the foot pegs relocated to give the Suzuki additional lean angle clearance. The frame changes amounted to nothing more than relocating foot controls and brackets to which they attached.
New instruments were fitted to the Indy in 1974 and included Suzuki's popular digital gear read-out and bigger idiot lights. The five-speed gearbox is identical to the transmission in the big 750cc Suzuki LeMans. The 550's clutch and primary drive are equally robust.
Suzuki went to the disc front binder in 1973. The rear drum brake and wheel have remained unchanged, as have the tire sizes.
Electric starting was in the first 550, and has remained without alteration. Most of the electrical components are the same as those used in the 750s. The plush saddle
and four gallon gas tank have been changed in very minor ways—a new piece of vinyl here and a fresh paint stripe there. Minute internal modifications appear in the parts books of each new Indy, but the motorcycle remains pleasantly the same. Unlike most re-vamped new models the GT550 has lost seven pounds since 1974 and the price has escalated only moderately. As Suzuki's most successful road bike, the GT550's reputation for dependability is a matter of record.
Source Cycle World